ipc: Simplify mutex_try_lock().

[dss.git] / ipc.c

diff --git a/ipc.c b/ipc.c
index 78533bee310a6f7b9b46cf811fb12623dc2f775e..c6f7e6b00f52c466ea051a40c188c739c7fd060b 100644 (file)
--- a/ipc.c
+++ b/ipc.c
@@ -13,12 +13,13 @@
 #include <stddef.h>
 #include <limits.h>
 #include <sys/param.h>
+#include <stdbool.h>
 
 #include "gcc-compat.h"
-#include "string.h"
+#include "str.h"
 #include "log.h"
 #include "gcc-compat.h"
-#include "error.h"
+#include "err.h"
 #include "ipc.h"
 
 #if (defined(__GNUC__) && defined(__i386__))
@@ -310,25 +311,21 @@ static int mutex_lock(int id)
        return 1;
 }
 
-static int mutex_try_lock(int id)
+static bool mutex_is_locked(int id)
 {
-       struct sembuf sops[2];
+       struct sembuf sops;
        int ret;
 
        DSS_DEBUG_LOG(("trying to lock\n"));
 
-       sops[0].sem_num = 0;
-       sops[0].sem_op = 0;
-       sops[0].sem_flg = SEM_UNDO | IPC_NOWAIT;
+       sops.sem_num = 0;
+       sops.sem_op = 0;
+       sops.sem_flg = SEM_UNDO | IPC_NOWAIT;
 
-       sops[1].sem_num = 0;
-       sops[1].sem_op = 1;
-       sops[1].sem_flg = SEM_UNDO | IPC_NOWAIT;
-
-       ret = do_semop(id, sops, 2);
+       ret = do_semop(id, &sops, 1);
        if (ret < 0)
-               return -ERRNO_TO_DSS_ERROR(errno);
-       return 1;
+               return true;
+       return false;
 }
 
 int lock_dss(char *config_file)
@@ -345,6 +342,8 @@ int get_dss_pid(char *config_file, pid_t *pid)
 {
        int ret, semid, key = get_key_or_die(config_file);
 
+       if (pid)
+               *pid = 0;
        ret = mutex_get(key, 0);
        if (ret < 0)
                return ret;
@@ -352,9 +351,7 @@ int get_dss_pid(char *config_file, pid_t *pid)
        ret = semctl(semid, 1, GETPID);
        if (ret < 0)
                return -E_NOT_RUNNING;
-       *pid = ret;
-       ret = mutex_try_lock(semid);
-       if (ret >= 0)
-               return -E_NOT_RUNNING;
-       return 1;
+       if (pid)
+               *pid = ret;
+       return mutex_is_locked(semid)? 1 : -E_NOT_RUNNING;
 }